Such a converter is described, for example, in DE 41 10 003 C1. This converter has three ports, a vacuum being applied to the first port, atmospheric pressure being applied to the second port and a mixed pressure of the first and the second port being applied to the third port which mixed pressure is supplied to a load, such as an exhaust recirculation valve, for example. Moreover, this converter comprises a valve means as well as a plunger-type armature fixedly attached thereto, which is displaceable by means of a solenoid so that the position of the valve means can be changed and the mixed pressure supplied to the load can be controlled. The valve means and the armature attached thereto are suspended from a membrane such that they are movable in the axial direction.
It is a drawback of such a pressure converter that the armature and the valve means can swing freely in the axial direction, whereby undesirable vibrations can be caused especially by engine vibrations or by pressure pulsations on the part of the connected components. This undesirable effect occurs particularly frequently in connection with vacuum pulsations.
Moreover, pulsations can occur in a state in which no current flows through the solenoid and the solenoid can exert no forces on the plunger-type armature and the valve means. Undesirable vibrations of the plunger-type armature and the valve means result in troubles in the operation of the internal combustion engine.